textproduct: Albany

WHAT HAS CHANGED

Temperatures and dew points lowered this afternoon due widespread cloud cover and the sfc warm front struggling to lift north of the ADKs, Mohawk Valley, and southern VT. Still monitoring snow squall potential this evening, and have increased lake effect snow amounts across the SW ADKs and western Mohawk Valley tonight into tomorrow morning.

KEY MESSAGES

1) Snow showers and some squalls expected late this afternoon and evening, mainly from the Capital District north and west, which could result in additional areas of hazardous travel. Light lake effect snow is then expected overnight into tomorrow morning for the southwestern Adirondacks and western Mohawk Valley.

2) A brief warmup is expected on Saturday, followed by a cold front passage and a return to well below normal temperatures again Sunday into early next week.

3) Monitoring a potential storm system that could bring accumulating snow to at least parts of the region early next week. Forecast confidence is low at this time.

DISCUSSION

KEY MESSAGE 1... As of 2:05 PM EST...Current sfc analysis shows a 992 mb low located southeast of James Bay, with its trailing cold front located back across the Great Lakes. The associated warm front is hung up across our region, with the Mid Hudson Valley seeing temperatures in the mid to upper 30s while the southern ADKs and southern Greens remain in the mid 20s. Snow from earlier this morning has come to an end, but additional snow showers ahead of the cold front are just starting to get into the western ADKs. Temperatures should gradually warm this afternoon and into early this evening as the warm front gradually continues to lift north.

This evening, there is good agreement from hi-res guidance in scattered snow showers and isolated to snow squalls developing as well. Timing looks to be 4-7 PM for the western ADKs, 7-10 PM for the western Mohawk Valley, upper Hudson Valley, and Capital District, and 10 PM to midnight for areas south and east of the Capital District. With the loss of daytime heating after sunset, there does not look to be much instability available, but with decent low-level convergence/FGEN along the cold front, some upper-level support, and moisture enhancement from the Great Lakes, still expecting a fairly linear character to the band of snow squalls. This line should begin to weaken once it gets south and east of the Capital District. As the snow squalls track through the region, brief reductions in visibility and a quick coating to an inch of snow could lead to hazardous travel conditions.

Behind the cold front, 850 mb temperatures drop to -12 t0 -15C, coldest across our northern and western areas. Temperatures should drop back into the 10s to 20s for overnight lows. The cold air moving over Lake Ontario, which remains relatively ice- free, will allow for band of lake effect snow to develop. Inversion heights around 800 mb and 25-30 kt 850 mb winds will allow for an inland extent into the SW ADKs overnight. As low- level flow shifts more to the W/NW, the band will drop south into the Mohawk Valley by late tonight or early tomorrow morning, potentially impacting the Thruway around the time of the AM commute. Short residence times of the band will keep snowfall amounts generally to 1-3." The winter weather advisory remains in effect for the southern ADKs through 7 AM Thursday due to the additional lake effect on top of what already fell this morning. Given the sub- advisory additional amounts, did not add southern Herkimer County, but will still mention the potential for slippery travel conditions there tomorrow AM. Winter weather advisory for Bennington County also continues until 7 AM tomorrow as the combination of lake moisture enhancement with westerly winds will lead to some upslope snow showers tonight, with additional light accumulations tonight.

The lake effect snow band should move south of the Thruway by mid-morning tomorrow. The band should also weaken, continue to drop south, and retract closer to the lake as high pressure building in from the west allows winds to weaken and 850 mb temperatures warm. Temperatures tomorrow will be in the 20s (terrain) to 30s (valleys) with overnight lows dropping into the 10s to 20s. Aside from the lake effect snow, generally dry conditions expected across the region.

KEY MESSAGE 2... Friday night into Saturday, a strong sfc low will track well to our north through eastern Canada. An associated warm front will lift north through the region Friday night or Saturday, which will allow for temperatures Saturday to reach the 40s for most of the region. Then, the system's cold front tracks through the region Saturday afternoon or evening, with a secondary cold front later Saturday night or Sunday. Todays 12z guidance has trended slightly faster with the system's cold initial frontal passage, so forecast highs have decreased a degree or two from the previous forecast. A few rain/snow showers will be possible with the cold front, but accumulations generally look quite minor. Will also mention that the warm-up looks quite brief, so this shouldn't really allow for enough snow melt to result in any ice jam or flooding issues.

Behind the secondary cold front Sunday, there is a strong signal for a shot of arctic air to move over the region, with the NAEFS already indicating 850 mb temp anomalies of 1-2 STD DEV below normal. Overnight lows likely will be in the single digits to below zero Sunday night, with highs Monday only in the 10s to 20s. Other than the aforementioned rain/snow showers with the front, generally dry weather is expected Sunday as a large area of high pressure builds over the region.

KEY MESSAGE 3... Where the area of high pressure sets up will be the key to the forecast for early next week. Flow aloft looks relatively fast and somewhat zonal, albeit with several embedded shortwave disturbances. One of these disturbances Monday may result in an area of low pressure bringing snow to the region, although some sources of guidance suggest that the strong sfc high will suppress this system completely south of the region. Many sources of guidance that keep the first shortwave south of the region have a follow-up wave behind the first one that could bring snow to the region. While forecast confidence remains low at this time, the WPC PWSSI shows a 30-50% chance for minor impacts from winter weather early next week, with the best chances across the southern half of our CWA.

AVIATION /00Z THURSDAY THROUGH MONDAY/

Through 00z/Fri...VFR conditions early this evening will drop in response to a line of snow showers that looks to cross the TAF sites between 02-06z this evening. Continue to highlight this potential with with TEMPO groups at PSF, ALB, and GFL with a PROB30 group at POU where a rain/snow is anticipated due to marginal temperatures. Vsbys should lower to IFR/LIFR for a brief time at KALB/KGFL/KPSF during the heavy snow shower with MVFR cigs. In the wake of these showers, flying conditions improve back to VFR for a few hours before lake effect snow develops upwind which may result in MVFR cigs reforming at ALB and PSF by 09-12 UTC. MVFR cigs then linger into the morning hours at both sites but improvements at ALB are expected in the afternoon which will be address in later updates. Otherwise, GFL and POU should remain VFR. South to southwesterly winds 5-10 kt winds continue through 03-06 UTC before winds shift to the west and increase with sustained winds 5-12kts and gusts up to 20kts through the day Thursday.

Outlook...

Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Low Operational Impact. Slight Chance of SHSN. Sunday: Moderate Operational Impact. Chance of SHSN. Sunday Night: No Operational Impact. NO SIG WX. Monday: Low Operational Impact. Slight Chance of SN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...Winter Weather Advisory until 7 AM EST Thursday for NYZ032-033- 082. MA...None. VT...Winter Weather Advisory until 7 AM EST Thursday for VTZ013.